Method of killing organisms and removal of toxins in enclosures

ABSTRACT

A method and kit of components for destroying organisms and toxins in from an enclosure such as a building. Temperature sensing probes are installed in the enclosure to indicate structure temperature and a recorder is used to record the temperature of said sensing probes in real time. Hot air is introduced into the enclosure through one or more ducts to raise the structure temperature to at least about 120° F., as monitored by the temperature sensing probes. This is sufficient to kill essentially all insects, bacteria, virus, dust mites, spiders, silver fish, fungi and toxic molds such as  aspergillus oryzae, aspergillus terreus, aspergills versicolor, cladosporium hergbarum, stachybotrys chartarum, penicillium aurantiogriseum, pencillium chrsogenum, pencillium glabrum  and  fusarium oxysporum . and the like. The air can exit through open doors and windows or through ducts to a filter assembly that captures the remains of the organisms. Ozone may be added to the heated air to improve efficiency. Preferably, air when extracted from an egress duct downstream of the filters improves air flow through the enclosure and filters. A typical building can be treated in six to eight hours.

RELATED APPLICATION DATA

This is a continuation of U.S. patent application Ser. No. 09/321,915,filed May 28, 1999, now issued as U.S. Pat. No. 6,327,812 on Dec. 11,2001.

FIELD OF THE INVENTION

This invention relates to methods of sanitizing buildings and otherenclosed spaces by killing and removing organisms such as insects,bacteria, virus, dust mites, spiders, silver fish, fungi and toxic moldssuch as but not limited to aspergillus oryzae, aspergillus terreus,aspergills versicolor, cladosporium hergbarum, stachybotrys chartarum,penicillium aurantiogriseum, pencillium chrsogenum, pencillium glabrumand fusarium oxysporum.

BACKGROUND OF THE INVENTION

A large number of methods have been developed for killing insects, suchas termites, in buildings. The most widely used method is tenting thebuilding, then filling the building with a toxic gas for a period oftime sufficient to kill termites or other selected insects. This methodis effective for killing termites and other insects. However, thismethod generally requires 12 hours to be effective, requiring buildingoccupants to move out businesses to be closed for approximately a threeday period to insure proper venting of toxic material and/or gas.Tenting the building with heavy tarpaulins requires workers to walk andarrange the tarpaulins on the roof, often damaging shingles or otherroofing materials. Food and medications must be placed in sealedcontainers or removed. Generally the entire building must be treated,even if the infestation is localized.

Because of the disadvantages of the toxic gas method, various othertechniques of varying effectiveness have been developed, using heatedair or very cold air to kill termites, electrical “shock” treatments,irradiation, non-ionizing, etc.

Typical of these is the method disclosed by Charles Forbes in U.S. Pat.No. 4,817,329, in which wood destroying insects, e.g., termites, arekilled by applying a heated gas, such as heated air, to wooden surfacesuntil the building surfaces are heated to a temperature, typically about120 to 135° F. Temperatures for killing other insects are said to besurprisingly close to this range. This method has been found to be veryeffective for killing termites. However, this method, using thedescribed temperatures, is not effective for other organisms, such asfungi, and toxic molds such as, but not limited to, aspergillus oryzae,aspergillus terreus, aspergills versicolor, cladosporium hergbarum,stachybotrys chartarum, penicillium aurantiogriseum, pencilliumchrsogenum, pencillium glabrum and fusarium oxysporum. Further, manyinsects such as mites, fungi, molds and the like are a serious healthhazard even when dead. Many people are allergic to the dust-like remainsof these organisms that can also cause serious health problems. This isa particular problem to persons suffering from asthma, bronchitis,pneumoconious and other respiratory ailments.

Therefore, there is a continuing need for improved methods of killingorganisms in enclosures such as buildings that are fully effective inkilling and eliminating substantially all such organisms, is non-toxic,can be performed in a relatively short time, is clean, dry and odorless,and removes a large proportion of the dead organisms.

SUMMARY OF THE INVENTION

The above-noted problems, and others, are overcome in accordance withthis invention by a method which basically comprises the steps ofpreparing the enclosure to be treated, such as a building by, removingall heat sensitive items, positioning heat shields, etc., positioningtemperature indicating probes at appropriate locations, inserted intobuilding structure, open spaces, etc., installing ingress ducts throughwhich an environmentally acceptable gas, such as air, can be directedinto the enclosure, allowing the gas to leave the enclosure by openingwindows, doors, etc. or by installing an egress duct or ducts for thispurpose, heating the gas and directing it into the ingress duct(s) wheninstalled and filtering gas exhausting through open doors and windowsand/or the egress ducts to collect organism remains and prevent themfrom entering the environment.

To increase system effectiveness, under some conditions, it is preferredthat a suitable quantity of ozone be fed into the heated air passingthrough the ingress ducts. Ozone aids in killing many organisms and willeliminate any chemical fumes, odors, etc. that may result from thetreatment.

To increase gas flow through the enclosure when egress ducts areemployed, it is preferred that a vacuum extraction system be provideddownstream of the filters receiving gas from the egress ducts. This willassure that almost all gas leaving the enclosure will pass through thefilters and increase the capture of organism remains.

It is, therefore, an object of this invention to provide a non-toxicmethod for destroying a wide variety of organisms including fungi, toxicmolds such as, but not limited to, aspergillus oryzae, aspergillusterreus, aspergills versicolor, cladosporium hergbarum, stachybotryschartarum, penicillium aurantiogriseum, pencillium chrsogenum,pencillium glabrum and fusarium oxysporum and insects in enclosures suchas buildings and the like.

Another object of the invention is to remove substantially all of theremains of the killed organisms from open areas in the enclosure.

Yet another object is to filter gases leaving from the enclosure toprevent the allergenic organism remains from entering the environment.

A further object is to accomplish the destruction of the organisms in arelatively short period.

Still another object is to monitor the temperature level throughout theenclosure to assure that all areas reach the predetermined effectivetemperature.

BRIEF DESCRIPTION OF THE INVENTION

Details of preferred embodiments of the invention are provided in thedrawings, wherein:

FIG. 1 is a schematic diagram showing components of the system of thisinvention; and

FIG. 2 is a flow diagram of the method of this invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIG. 1, there is seen a schematic diagram showing thecomponents of the kit of this invention in use treating an enclosure 10.Typically, enclosure 10 may be a house, barn, shed, a business buildingor some portion of such a building. An enclosure 11, such as, but notlimited to conventional tenting may be required to treat the exteriorsurface of enclosure 10.

A plurality of temperature sensors 12 are positioned at predeterminedlocations to monitor temperature of the structure. Typically, thesesensors have thin, elongated, tips that can be adhered to or pushed intowood or other materials or into suitable sized holes drilled into suchmaterial so as to measure the surface and/or internal temperature.Sensors 12 may be wired to a console 14 which displays and records thetemperature at each sensor in real time for future reference.Alternatively, the sensors may be wireless or infrared, transmitting asignal to console 14. Typical sensors, as for way of example and not byway of limiting, include thermal couples, thermistors, or the likeconnected to a computer and/or a strip chart recorder. Thermocouples canbe purchased from Togam under the model number 875F or any othercommercial vendor having an equivalent sensor.

One or more heaters 16 heat a gas to the predetermined temperature.Preferably, the gas is air, although any other environmentallyacceptable gas, such as nitrogen, may be used if desired. The gas isheated to at least a temperature lethal to the organisms to bedestroyed. For a more complete disinfection, the gas temperature ispreferably at least about 155° F., with optimum results generally beachieved with temperatures in the range of about 120 to 300° F.

Any suitable heater may be used. A gas burning heater, such as aconventional propane heater is preferred as being particularly efficientin heating air. Any other heating arrangement, such as electricalheaters, may be used if desired.

Heated gas from one or more heaters 16 is directed to a blower 18 (whichmay, if desired, be a component of the heater) which directs the hot gasinto enclosure 10 through at least one ingress duct 20. Generally, aplurality of ducts 20 will be used to achieve the optimum distributionof hot gas throughout enclosure 10. Ingress ducts 20 preferably includevariable flow dampers and may be moved while the system is in operationto achieve uniform temperatures in all areas being treated of thestructure, as sensed by sensors 12 and observed at console 14.

When utilized, at least one egress duct 22 is provided to allow the gasto leave the structure. While it is preferred that enclosure 10 bemaintained at a pressure slightly above atmospheric pressure as the hotgas brings the building elements up to the desired surface andpenetration temperatures, the positive pressure differential allows thehot gas to vent through open windows, doors, etc. to and carries awaythe remains of the destroyed organisms upon venting. When the structureis sealed the duct or ducts 22, like the open windows and doors, cariesaway the remains of destroyed organisms. A filter assembly 24 receivesgas from an egress duct 22 and removes the remains of the organismspreventing them from reaching the environment. Typical filters areavailable from Therma-Stor Products, Madison, Wis., under the GuardianHEPA system designation as for example and not by way of limitation, aUV filter is desired, however other filters suitable for the purposeintended can be utilized.

For optimum effectiveness, it is often desirable to increase gas flowrates by adding a blower 26 or other gas extraction means downstream offilter 24 to aid in extracting the gas from enclosure 10. This forcedextraction increases the efficiency of filtering of the gas by filter24.

In some applications, the introduction of ozone gas from ozone generator28 into blower 18 or ingress duct 20 is highly desirable. This resultsin oxidation of organic contamination, such as molds where layering hasoccurred. Ozone generators suitable for use here are available from RGFO³ Systems, Inc., under the TURBOZONE® trademark. Equivalent ozonegenerators suitable for the purpose intended can be used for thepurpose.

In the operation of the system of this invention, the first step is toprepare the building, as indicated in block 30 of FIG. 2. This basicallyinvolves removing all heat sensitive items from the enclosure or, insome cases, covering heat sensitive items with thermal insulationmaterial. All material that has a flash point below the maximumtemperature to be used must be removed.

Next, a plurality of temperature indicating probes are placed inpredetermined locations within the enclosure as indicated in block 32 toassure that the required temperature levels are achieved. In some casesthe probes can be read directly, although preferably they are connectedby wires or wireless means to a console, so that all probes can bemonitored conveniently and the data recorded in real time.

At least one ingress duct and when the enclosure is sealed at least oneegress duct are then installed as indicted in block 34. Generally, aplurality of ingress ducts is preferred. Although each duct may enterthe enclosure separately, the use of one ingress entry duct connected toa manifold from which plural ducts extend to predetermined locationswithin the enclosure is preferred. When filtering the exiting gas, ductsmay enter through any suitable opening, such as an open window or doorwith the remainder of the window or door blocked by a panel.

When everything is positioned, the gas (preferably air) is heated asindicated in block 36 and directed into the ingress duct(s), asindicated in block 38. If desired, ozone can be optionally added to thegas stream at this point, as indicated in block 40.

Air leaving through egress ducts may be filtered to remove the remainsof the destroyed organisms, as indicated in block 42. The filter systemwill inherently impose some back pressure on the egress ducts andenclosure. Back pressure is desirable to assure surface exposure andpenetration of the heated gas to all parts of the enclosure, butexcessive back pressure should be avoided. Therefore, it is generallydesirable that an air extraction system, as indicated in block 44, beincluded to increase air flow through the filter system and limit backpressure.

At any time during system operation, the ingress and egress ducts may bemoved to assure uniform temperatures throughout the structure, asindicated by the temperature probes and temperature monitoring console.

Flow of the heated air through the enclosure will generally be continuedfor about 1 to 6 hours to provide optimum results. Usually the entireoperation from preparation of the building to removal of the equipmentwill take six to eight hours.

While certain specific relationships, materials and other parametershave been detailed in the above description of preferred embodiments,those can be varied, where suitable, with similar results. Otherapplications, variations and ramifications of the present invention willoccur to those skilled in the art upon reading the present disclosure.Those are intended to be included within the scope of this invention asdefined in the appended claims.

We claim:
 1. A method for killing organisms and removing of toxicsubstances from an enclosure, which comprises the steps of: providing atleast one ingress duct communicating with said interior of saidenclosure; heating an environmentally acceptable gas to a temperaturelethal to organisms comprising insects and at least one of fungi andbacteria; directing said heated gas into said enclosure through said atleast one ingress duct for a time sufficient to raise the temperature ofsaid enclosure to said lethal temperature to thereby kill saidorganisms; applying a pressure differential to said enclosure relativeto atmospheric pressure to draw said heated gas out of said enclosure;filtering said heated gas to remove from said enclosure any fineparticulate remains from said organisms that are suspended in the heatedgas; and exhausting said filtered heated gas from said enclosure to anexternal environment such that the particulate remains are substantiallyremoved from said heated gas before its exhaustion.
 2. The methodaccording to claim 1, wherein said extracting step further includespassing said heated gas through a HEPA filter.
 3. A method forsanitizing an enclosed structure having an exterior and an interior,comprising the steps of: disposing at least one temperature-indicatingdevice within said enclosed structure; heating a gas; directing heatedgas within said enclosed structure so as to maintain a flow of saidheated gas within said enclosed structure; monitoring the temperaturewithin said enclosure using said at least one temperature-indicatingdevice during at least a portion of said directing step, to determinewhen said enclosed structure reaches a sufficiently high temperature forsanitizing said enclosed structure; filtering said heated gas to removesuspended particulates in the heated gas from said enclosed structureduring at least a substantial portion of said directing step; andexhausting said heated gas from said enclosed structure by applying avacuum to said enclosed structure so as to draw the suspendedparticulates out of said enclosed structure, wherein the suspendedparticulates are substantially removed from said heated gas beforeexhaustion from said enclosure.
 4. The method according to claim 3,wherein said sufficiently high temperature is at least about 120° F. 5.The method according to claim 3, wherein said filtering step furthercomprises passing said heated gas through a HEPA filter.
 6. The methodaccording to claim 3, wherein said filtering step further comprisesdrawing a vented portion of said heated gas through a filter.
 7. Amethod for exterminating toxic organisms in a structure, said methodcomprising the steps of: heating a gas; directing said heated gas in aninterior portion of an enclosed structure so as to heat at least saidinterior portion to a temperature that is hot enough, when maintainedfor a period of time, to kill toxic organisms comprising at least one offungi and bacteria; maintaining an interior of said enclosed structureat not less than said temperature for not less than said period of time;and filtering said heated gas from said enclosed structure during atleast a substantial portion of said maintaining step using a filteroperable to capture suspended remains of said toxic organisms; andexhausting said heated gas from said enclosed structure by applying avacuum to said enclosed structure so as to draw the suspended remainsout of said enclosure, wherein the suspended particulates aresubstantially removed from said heated gas before exhaustion from saidenclosure.
 8. The method according to claim 7, wherein said temperatureis at least about 120° F.
 9. The method according to claim 7, furthercomprising disposing at least one temperature-indicating probe tomonitor temperature at at least one location within said enclosedstructure.
 10. The method according to claim 9, further comprisingconnecting said at least one temperature-indicating probe to a consoledisposed outside said enclosed structure.
 11. The method according toclaim 7, wherein said filtering step further comprises passing saidheated gas through said filter, said filter comprising a HEPA filter.12. The method according to claim 7, wherein said filtering step furthercomprises drawing said heated gas through the filter using a downstreamblower.
 13. The method according to claim 7, wherein said filtering stepfurther comprises removing said heated gas from said interior portion ofsaid structure during at least a portion of said filtering step.
 14. Themethod of claim 13, further comprising returning filtered gas to saidinterior portion after said filtering step.
 15. The method of claim 7,wherein the exhausting step further comprises applying a suctiondownstream of said filter.
 16. The method of claim 7, wherein saidheating step is performed outside said enclosed structure.
 17. Themethod of claim 7, wherein said directing step further comprisesdirecting said heated gas into said interior portion using at least oneduct.
 18. The method of claim 7, wherein said maintaining step furthercomprises maintaining said temperature for not less than about one hour.19. The method of claim 1, further comprising covering heat sensitiveitems within the enclosure with thermal insulation material.
 20. Themethod of claim 1, further comprising remotely monitoring temperaturewithin said enclosure.
 21. The method of claim 20, wherein themonitoring further comprises communicating at least one temperaturesignal wirelessly to a console located outside said enclosure.
 22. Themethod of claim 3, wherein the monitoring step further comprisescommunicating at least one temperature signal wirelessly to a consolelocated outside the enclosed structure.
 23. The method of claim 3,further comprising covering heat sensitive items within the enclosedstructure with thermal insulation material.
 24. The method of claim 7,further comprising covering heat sensitive items within the enclosedstructure with thermal insulation material.
 25. The method of claim 1,further comprising monitoring temperature at at least one locationwithin the enclosure.
 26. The method of claim 25, wherein the monitoringfurther comprises disposing at least one temperature-sensitive probewithin the enclosure.
 27. The method of claim 26, wherein the monitoringfurther comprises communicating a signal from the at least onetemperature-sensitive probe to a console located outside the enclosure.28. The method of claim 7, further comprising monitoring temperature atat least one location within the structure.
 29. The method of claim 28,wherein the monitoring further comprises disposing at least onetemperature-sensitive probe within the structure.
 30. The method ofclaim 29, wherein the monitoring further comprises communicating asignal from the at least one temperature-sensitive probe to a consolelocated outside the structure.